SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '46f78a028313a2cffc2aa61926f66218e806f15173646d8ab4201c8e1dd2236c' 
  AND token = 'bRtywVKmU7Mt/UUvSHrShTsVbxflATa/VCjo0ms1w3Q=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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