SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e2aad691f8f1016bc753ee941bba131974627d5368b5e246bd7db96e79f8840d' 
  AND token = 'HeIzM1nRaLhovtfcE7awp+PWaK9gh81VcP0UhNy1R+Q=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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