SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '027df8d42509e0ad9b10bd39fac00a2394b06830f3f864ba803194d83fbe4b72' 
  AND token = 'wsW65FcMBWaQOT0WJdlILS7qA+xYKl+AN8YmvkIjg74=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00037

JSON explain

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