SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1f544e56dc2578ce5b77e02f2b5396d6466287a69cdbd77a29b78ca788f207c2' 
  AND token = 'OMHNaen9f47XplUIFAVeXZVK31OyzkeEmirX7rtLkI8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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