SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'fe1012b91445ea4373c8dc9138bae38a3e5e806d4708246e14c33c64079109cb' 
  AND token = 'ETbe+aoKJW1xFcWvgWnFar/ZAp+IceI5Ez8q5ti+qLc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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