SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'da72dab6418f349fe636a5c92ec958748428397a636952aa7aed2a2cb2bb622c' 
  AND token = 'Fg/AnBfwDmSbUPql5JD/SXsiMhwt1LTyMMYfZla8iws=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

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