SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '747cb60c95fc9d3a00f60eac0590efbe7e3e3c51458777a51c2b632cf31782d2' 
  AND token = '5lx0CqAH8oOIJDUqEXUPaGlyhqoLK3lKAreaw0COXAM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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