SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'd52bb4c0dd24f3847bbb883e8d2a8e76b33b1182c9e1e258d937198ce5030e0a' 
  AND token = 'NTHoF6zMyGvsHAs2L/+bfzp6jcvl5v/jr8A3FdCrK4M=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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