SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '66697552aafaf9d7f87885700b3f02e7c5e0352f5cc699982f11836a6f008cb5' 
  AND token = '7gP11GKvcLEI5snKs74VOcb1u3eCiFwXPMdDfibjtKE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00039

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}