SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '32c6577cb951966e493c5127f334c8686ef5550f5fe2d26c8ee25444f4f3f7db' 
  AND token = 'hhL2AdjzPyAUHQeB3n7VSPZREcnzJlzOBREml7kH0Yw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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