SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '86d51c22366d9b3dd74518ed67f2a5c20553290f2f2c59d777280dc1fd4e1cb3' 
  AND token = 'YJ3H7G/4EGLmjq2qlfHv8hDMm4BBBBMxH/tP11SjHgM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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