SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0487dff4eb19aaf3e9c43cffd1cc3ed76e2b5c3928dfeab25c76af54af26f738' 
  AND token = '+HGEI4Slh+PPSHMXbRVLHBwMIWopQ2p3YQCEYAWAHKg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00035

JSON explain

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