SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '6800d66bb9e4d6320776d7e17b3773ad030c352b529b5ef177db9a9baca6ad29' 
  AND token = 'NTMDaWuoH5b3juCYvjBETJjigsll9q5MZg4M/YPGh9I=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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