SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '617af513c3605e96e32606a665408e77e78261fffd238883bda7fcd1e59f77e3' 
  AND token = '0ggX5qnXvdMSzAQ6sbGgd5ENNEVBYRU+K44ABNoLOr4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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