SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a27a06045dd1479841381af22ff7b7b25ba9cedca3aa9f3dcf36f66669563577' 
  AND token = 'LF/AN35aOQ8whWgBOG/hexjr98PAYG3+/gFBV2JQ1gM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00054

JSON explain

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