SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '582ceb7ceede09bd271a752129e6ebfbb5bd994a23bb5db712fdd8ae25c87383' 
  AND token = 'mn3511CR4t0XYTXmJQgLYu+BpUxRY8oKK0YczH4YOms=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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