SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8856e46289c1ce7b5d1231f0296230a5a91c1cf9aaf2dc9bdab80a6605c299f7' 
  AND token = '44pFAnOuRQJdrKJ4S0oWDQmS6LT09qOFGajcXiT1Bqs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00048

JSON explain

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