SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'dcf46a9343f682a251cd10592019d08204c2ed0c182742d4fed1ff62f5bb1f55' 
  AND token = 'BXHbP7uzGrg86mnOFlJVnfrvrLrMSZ3CgXPIyROYo1w=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

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