SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ce345de211e8d4d64ab876ddd41479a1e8c9c903215450ded2d2d896fca7e478' 
  AND token = 'Z50HKpkD1eCpwSPn7U/GCVkcypjNtnE/+Xdk6JMOG3w=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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