SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'dd27f34c24ec910c9662f417578a8dca9b8d84a11234df3efb9c9672af5c513b' 
  AND token = 'tz6csdb3FSIGlEXNR8zMXL4+ajdd7Zty0xceWsdG8SU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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