SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '14247911cecb21526dc0caed088d2a27c18e4ee5eee7b92083c433aa3cf022eb' 
  AND token = 'hRSAipBV3AdQPSQY/dLfz0D0Dl02ey3N2kFkGc/A3M8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00015

JSON explain

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