SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '56c195c57036c9d86ca941055dcf34a188d62858b5da441efb0bfbfdd59330b9' 
  AND token = 'Lc73d9h5J/TouMnywKg9q8Kxmd3gCjMrBguDi1MmbB8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

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