SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'aae79b4b3fdda35f7b10798bd866d1fcc143b3393e7ce8039c77a94a1a43d4bd' 
  AND token = 'MNbmqVOgELHHEX1E/Af7fw1gwEMmLF98Z5DPI8k+DO0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00035

JSON explain

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