SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'fe3d6cd72facce7fa248f6744a3d15d066a23e95748245cdd3a520b041209a7b' 
  AND token = 'CxowmSoqETw5MZGINHKXWsUyP+dB1AnhcacUXscxPUg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00037

JSON explain

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