SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'a98e747a216d6508db2bf5a761a2f565f77106c97551029d319e3721008fa869' 
  AND token = 'PCXiwbbx3ErnctZRHVC1nasuXX+ykiXg6vRhZzP0Loo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

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