SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '349cb704946b73ce663efea2a47a522b5faf02a0c6feaff9e7557619e2ef4408' 
  AND token = '25tGi1dpY9k6r2c4ijygX8LOj8dOZzJsZC1At9HPvgg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

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