SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '61f5d8c953bb9d2205feee5e182f152f8832bbbdd45d7c817b31644ae09d5063' 
  AND token = 'fxsLf2wxbu+aApVcjpBPmEEmGTzZvqNFlMM7lf1ks7o=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00037

JSON explain

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