SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd57503cd0b368b89fdb3e7110d3a1ad8d5d2fa8e6b2a41072bd71ccf7dac5034' 
  AND token = 'nXgW7w3vs6v0BcEeAo+cVa3yMlan/lBH2vQ2URGW1iw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

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