SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '70a0304c9dad9af92d4adbf6c1b386f45cead80f14629f49c53454273c292c49' 
  AND token = 'evFRFh8kofLqk7/znXxjI6U6rGlkngM7OoPLtaAx1BI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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