SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'fc6fd98a7a5dde3cbd39c048fc400fed101f35f7fd924e02106bae9bc1a2b440' 
  AND token = 'o1pC64+qpOns7+jHIazHJvbYQnWCU7zGLFyB2aENGBQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00039

JSON explain

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