SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b2ce0934f79fa2b2bc1cbea9543db43dfdfad7219579012b2fe346451e1a4289' 
  AND token = 'RFoZdlqhmDMsERwjec+GrORmqtjmI9T5ppIMHgHDA48=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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