SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5ed6bf6c1092a7ce833281b18ba9c274dc1974213f6b3289a79867286aebd3bd' 
  AND token = '5JFDqEdTsoOeJ331/Lgv7RANPwQ99sFstckGnu2013U=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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