SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f8dff33a67fa7455f7b5f9a5a123056be9286f67e698b74eae4d5b276020dab9' 
  AND token = 'NTQUI8J0RBRqulqcXRbLj0HyYFaiiqc6+Pcro9vohCs=' 
  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"
    }
  }
}