SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'cfe229be316016d8a6ad479296813b8d5d7b6e11bc451c43b7a073f896435322' 
  AND token = '9B75AvuPg2OTCu9tC7bq+1GLJZ5Twf4/QqG3ck1Fv04=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}