SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '548c623b66383673d4509d0142177ad9bfb786abf760d4d7bc368db2fa90800a' 
  AND token = 'GyQPM+hHGmO2kOUpSTim00cPcix7SFq1E+TQb6hw70s=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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