SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3882af57078b92732dfcdcc8f31cc56dbd97149daa088144aa5a4e925f6f4358' 
  AND token = 'PG46K4ADdGTSA/hFpwHHRVyY8zgZgIRiJvVQCwtrAIw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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