SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0f28547cab5450f2fee1cd5f5bf8c00b92821e6532b94ed2cc03311578684786' 
  AND token = 'kTaLRB2fBWJzFFviXgbzZoUk9CHIZXge3HpjWOCYMmc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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