SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0d6125b7ad451d2ad149b2614a0f5c6c34782419ffe9ec4c05033544fcbc9373' 
  AND token = 'IWcGK7/nTkcqBEBneGHykiO4Yg0GGEaQD1D82qaz31c=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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