SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e57f9aeef76c6a4b50d4497fd62667f57fdbcd9170d2e67a58e0dae8ce28006a' 
  AND token = 'vNbTnpndh7QLgibRnnk8VARRp8V12bpcCQONOtUgi6k=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00042

JSON explain

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