SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b96cf492fde95db100ddec306b4e0da16c52f6288e7ddfa6f70e5eba6b025873' 
  AND token = 'fEPOD8Kq6W2ZANBWCDBArquJ+9p+q2qtbfxEWzLmKw4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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