SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd4e9bebe6bb0ee647b2a9acd56bebfe30235747dc7b0bde819897b1c43199f5b' 
  AND token = 'uNk0IYgVoei7EFHNFYAI16Cp2BvtXQtAAjUoeAfGTHw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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