SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c2b6e078425300e92477b7fba0d6b2e9ef89942fc5e038d0987e726c3ea9eccb' 
  AND token = 'LpfrQsnNYUIbcmzfCVzqyWfnqPojEGBbPMIxd/gus3M=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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