SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '32b1476bd00d89f45f0b58a56fdf21158f51715554b546ae7cb2dfcdb78aad83' 
  AND token = '3hYszA/swTOqtbdXKcI/W9vRTU1KZm85ShaJ5yWHzUM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00049

JSON explain

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