SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4dd8e75040fa164df333322d10e076affb5c310a38914750925592258bede32e' 
  AND token = 'cVjWldzE1oR/pdRGFzb7J/ZWpwLQmvaM14GUY8cIdP4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00040

JSON explain

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