SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '2f60503beb5b750230c198be9b3f5b66a3229f848c1566d3187470be4001a242' 
  AND token = 'kLOBS7kyZPnjAAjb/LElU5CRUE1tbNcDyiI/DjH/FAo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00039

JSON explain

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