SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c3127ea89a1f0d861afc8029ee881d87206cd42950639aa9d7d16831e2623f54' 
  AND token = 'uh1Q5JYYwViwt7GVNnkLdyLph8bftd7MFznaGkb2TGU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00097

JSON explain

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