SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8548a4c0662696ea3228940fb90989c2b97f3b7b8ef29168fb5537e37a255444' 
  AND token = 'HOl2F2bCIj1iKgnWeooFrBwDBlaNlmv6hyqzF1Nglpc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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