SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ca7f66836904d6773e1c71bfac5f5dcd436fbc607504ee0258df379c1f745730' 
  AND token = 'uzntFA4nJmEShQBgCs1fHCfAWps6ayuEzxYRESee5JU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

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