SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ce1bd274ef3c88e06ba5c4537be95957460a814f2d39fb4c18856b17c85e71b2' 
  AND token = '0XqdlqYaTMj3p29mdG2LgrzE+bz6tFDwldgy0ybEFPk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

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