SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '66850d3a52bb6649e8ff703a8311dbd970d2bc5c1f329664557d9c0361598ca3' 
  AND token = '0XaMstzwZ/EgpSW27s9SxslnQU4/2BhsXSZgLvW46Xc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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