SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'f5d23cd18f2b70140dc0524b57da79f7d1e0be76c087aefc68f54faa1c184968' 
  AND token = 'xEA0qsQiHCbbSVoHpMSB6Kf2LlInHfXDHQKeewjlM+4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00044

JSON explain

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