SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '87f35742942b63cbfde43e4047dade34549ba0832ee325654897085b2b34efce' 
  AND token = 'ygHXbcr7Cj2n/mVJPJLAepIVQ6HivFzcllcU8k1Ut3o=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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