SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5a98c1bd1dfb1968b2c800ecedcd52dbe27f88e13742481df4792a69c486ba9a' 
  AND token = 'yozvhfYmpxNVvwzj29frhA3wBknF7ZzqZ4U+NqpDKwE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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