SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4e2938b0141cb95d6a9dc03f2b02dbbef792d7d8a30f03cb974e7f1d8959f26e' 
  AND token = 'GNkwgoQs06c2imABCbziUiRo5l/3Kgeqiw64ER+r6Ig=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00041

JSON explain

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